UNIVERSITY  OF  ILLINOIS, 

Agricultural   Experiment  Station. 

CHAMPAIGN,  AUGUST,  1894. 


BULLETIN    NO.     K. 


THE  RUSSIAN  THISTLE  IN  ILLINOIS. 

The  Russian  thistle  is  spreading  rapidly  in  several  of  the  north- 
western and  western  states.  Introduced  into  the  southern  part  of  South 
Dakota  in  1873,  it  is  now  abundant  over  large  areas  in  both  South  and 
North  Dakota,  and  is  also  growing  in  different  parts  of  Nebraska,  Kansas, 
Minnesota,  Iowa,  and  Wisconsin.  During  the  present  season  it  has  been 
found  in  at  least  nine  different  places  in  northern  Illinois  and  is  reported 
to  have  been  found  in  northwestern  Indiana.  George  P.  Clinton, 
Assistant  Botanist  to  this  Station,  seems  to  have  been  first  to  recognize 
the  weed  growing  in  this  state,  at  Polo.  It  is  quite  probable  that  a 
few  plants  are  growing  in  other  places  in  the  states  last  named,  as  rail- 
way transportation  of  live  stock,  grains,  or  other  farm  seeds,  or  hay  from 
the  infested  regions  affords  a  ready  means  for  the  distribution  of  the 
seeds  of  this  and  other  weeds. 

While  there  is  reason  to  believe  this  weed  might  not  become  so 
serious  a  pest  in  Illinois  as  it  is  in  the  Dakotas,  even  if  allowed  to  become 
common,  it  is  exceedingly  important  that  this  result  be  prevented,  and 
this  can  be  done.  There  is  little  reason  to  believe  that  there  is  any  great 
number  of  plants  now  growing  in  any  part  of  the  state.  They  are, 
usually,  of  such  size  and  appearance  that  they  can  easily  be  seen.  The 
plant  is  an  annual.  When  pulled  or  cut  at  this  season  it  dies  soon. 

This  Station  has  received  specimens  of  the  weed  found  growing  at 
nine  different  points  in  the  northern  part  of  Illinois:  Chicago,  St.  Charles, 
Hampshire,  Davis  Junction,  Polo,  Savanna,  Oregon,  Nachusa,  and  Peo- 
tone.  The  specimen  from  Chicago  was  found  on  waste  ground  near  the 
lake  shore;  that  from  St.  Charles  was  from  waste  land  near  a  foundry 
receiving  material  from  the  northwest;  all  the  others  from  railway  em- 
bankments or  along  their  right  of  way.  These  facts  suggest  that  in 

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BULLETIN    NO.    35- 


'  August 


RUSSIAN  THISTLE — A  BRANCH. 


1894-]  THK    RUSSIAN    THISTLE    IN     ILLINOIS.  423 

and  -about  Chicago,  Peoria,  and  other  cities  with  large  railroad  traffic 
from  the  northwest,  along  railroad  lines,  especially  in  the  northern  part 
of  the  state,  on  the  roadside  and  waste  land  near  these  railways,  and  about 
establishments  handling  material  from  the  northwestern  states  are  the 
places  where  this  weed  will  most  probably  be  found.  But  any  farmer 
who  has  purchased  grain,  grass,  flax,  or  other  seeds  may  have  the  weed 
growing  on  his  farm. 

This  bulletin  is  designed  to  urge  the  importance  of  farmers,  road 
commissioners,  and  railway  agents  and  section  men  looking  for  and 
destroying  the  weed  wherever  found,  and  to  enable  those  not  familiar 
with  it  to  recognize  it. 

The  U.  S.  Department  of  Agriculture  has  published  a  valuable 
bulletin  (No.  15,  Division  of  Botany)  giving  a  full  discussion  of  the 
history,  distribution  and  means  for  eradicating  the  weed.  This  bulletin 
can  be  obtained  by  applying  to  the  Department  at  Washington.  It  is 
illustrated  with  good  pictures  of  the  plant.  Two  of  these  have  been 
reproduced  for  this  bulletin;  one  a  picture  of  an  average  plant  at  or  near 
maturity.  This  picture  was  made  from  a  photograph  taken  by  the  Wis- 
consin Station  of  a  plant  found  growing  on  a  railroad  embankment  not 
far  from  Madison.  The  other  picture  'is  of  a  branch  of  a  plant  show- 
ing form  and  size  of  leaves.  Comparison  of  any  suspected  plant  with 
these  pictures  will  enable  any  one  to  identify  this  weed. 

The  plant  is  not  a  thistle,  and  does  not  look  like  one.  Russian 
tumble  weed  would  have  been  an  appropriate  name.  The  plant  much 
resembles  the  common  tumble  weeds  of  the  west.  When  mature  the 
stems  are  more  woody;  the  spines  or  little  thorns  are  hard.  Sometimes 
the  plants  are  very  compact,  nearly  round.  Sometimes  when  growing 
close  together  they  fail  to  have  the  rounded  form.  They  may  be  one, 
two,  or  three  feet  high,  and  from  eighteen  inches  to  six  feet  across.  The 
leaves  are  very  small,  as  are  the  flowers  and  seeds.  At  this  season  and 
later  the  stems  have  a  purple  or  rose  color.  After  September  ist  the 
seeds  may  be  sufficiently  mature  to  grow.  If  the  seeds  are  formed,  the 
plants  should  be  burned  as  soon  as  dry.  Left  to  themselves  they  do  not 
usually  break  off  and  roll  or  tumble  until  after  hard  freezing.  It  has 
been  estimated  that  an  average  sized  plant  may  have  20,000  to  30,000 
seeds,  and  it  may  carry  these  long  distances. 

It  is  suggested  that  where  plants  are  found  before  the  seeds  have 
formed,  one  or  more  specimens,  plainly  labeled,  be  placed  where  they 
may  readily  be  seen  by  parties  interested,  who  may  thus  learn  to  recog- 
nize them.  It  is  also  suggested  that  it  is  always  safe  to  destroy  any 
weed,  even  though  it  be  not  recognized  as  an  especially  troublesome 
pest. 

This  Station  will  identify  weed  specimens  sent  to  it,  but  it  is  urged 
that  their  destruction  should  not  be  delayed  for  such  identification. 

G.  E   MORROW,  Agriculturist. 


424 


BULLETIN    NO.    35, 


[August,  1894. 


UNIVERSITY  OF  ILLINOIS-URBANA 


